A subscriber to services in a mobile radio network can benefit from a large number of different services provided by the mobile radio network. Besides basic bearer services such as speech and data calls, most mobile radio networks also provide supplementary services such as call forwarding, virtual private networks, pre-paid etc. In most standards for mobile radio communication, some of these supplementary services are standardised and hence provided by all mobile radio networks based on the same standard. However, many supplementary services are also specific to a certain mobile radio network, and do not exist in other mobile radio networks based on the same standard. If no special action is taken, a subscriber to such a network-specific supplementary service will therefore not be able to use the service when he leaves his home mobile radio network.
In the standards of Global System for Mobile communications (GSM) and Universal Mobile Telephony System (UMTS) a network feature has been implemented to address this problem. This network feature is referred to as Customized Application for Mobile network Enhanced Logic (CAMEL), and introduces a possibility for the mobile radio networks involved in a call to/from a roaming subscriber to exchange information about the services to which the roaming subscriber subscribes. CAMEL is described in the GSM Technical Specifications 02.78, 03.78, 09.02, and 09.78 as well as in the 3rd Generation Partnership Project Technical Specifications 22.078, 23.078, 29.002 and 29.078.
An apparatus comprising a database, a generator and a data providing device wherein the generator generates a list of preferred wireless carrier identities based upon a selected class of service, predetermined national accounts and predetermined home market areas is disclosed in U.S. Pat. No. 6,148,197.